The contents of all references, including articles, published patent applications and patents, if referred to anywhere in this specification are hereby incorporated by reference.
FIG. 1 shows a schematic showing cross-sectional view of human's gastrointestinal (GI) system (from mouth to rectum). Diagnosis of disease in whole GI tract is very limited using today's invasive endoscopic technique. Diagnosis of problems in the small intestine has been very difficult. Push endoscopy is the most widely used method of observing issues in the small intestine. Push endoscopy is a procedure in which an endoscope is pushed through the mouth through the upper gastrointestinal (GI) tract into the small intestine. Only between 120 and 150 cm of the small intestine can be examined with this method. The small intestine is between 3.75 to 8.25 meters so only a portion of the intestine can be observed. Most of the deep intestinal issues or problems are undiagnosed using standard endoscopy. In addition, standard technique is not only painful to patient, but also it takes longer time going through whole diagnosis procedure based on this standard endoscopy method. It is highly desirable to have a method which is takes less or no time for patient in diagnosis procedure.
Recently, wireless video capsules have been developed to be able to observe the small intestine by taking and transmitting pictures as the capsule is passed through the small intestine. The capsules usually have an optical dome, lens, illuminating LEDs, CMOS focal array, batteries, electronics, wireless transmitter. The small capsule (the PillCam small bowel (SB) M2A, GIVEN Imaging Inc.) measured 26 mm in length and 11 mm in diameter. Similar size capsule, named EndoCapsule, marketed by Olympus later is clinically approved. The capsule, when ingested, will travel down the esophagus through the stomach and through the small intestine. The battery will last about 6 to 8 hours taking two pictures per second. Pictures are wirelessly transmitted to a data recorder that is attached to a belt around the waist. The capsule moves too quickly through the esophagus to take enough pictures at 2 pictures per second. The capsule also cannot take pictures of a large part of the stomach. The battery will run out before entering the large intestine so the large intestine will also not be observed. Rate of transmission through the small intestine will depend on the individual patient. A rate too fast beyond 2-3 cm/sec with the current rate of 2 sec/frame could result in missed detail.
Longer battery life could allow the capsule to take (i) more pictures at (ii) a faster rate and (iii) to last longer also (iv) to observe the large intestine. Battery capacity is related to battery technology and size. Present battery technology that will fit into the capsule is limited to about 60 ma-h. This is a major limitation of making the capsule more universally accepted. Because of the limitation on battery life, many approaches for slowing down or strategically stopping the capsule for more detailed images are infeasible. Slower or more controlled mobility would allow more observation down the esophagus and more time controlled in the stomach. All this additional information is collected taking additional time that is not available based on current battery life.
With extended energy capability there is then no limitation to the time spent stopping and viewing specific areas to better diagnose internal issues. With more energy available some of the disadvantages of the capsule can be overcome and more feature could be incorporated into the capsule. For example, features (i) to take more high resolution images, (ii) to retrieve tissue from suspicious areas, (iii) to collect fluid samples and (iv) perform cytology brushing could be added. All these additional features require additional power supply. With that need in mind, this invention is a wireless ingestible capsule which employs use of rechargeable energy sources and/or energy generating sources. The most importantly, with incorporating the energy generation source is not only replace the battery, as a major power supply, but it also provides more advantages to make the capsule more small form-factor, even if it needs a small battery, medically friendly to all ages of patient.